#!/usr/bin/perl -w

# dnsx.pl - by dual
#
# Automates zone file transfers
###############################


use strict;


# Declare
my $domain;
my $output;
my $where_to_print = 0;
my $usage = "dnsx.pl -
Automates zone file transfers
Usage: perl dnsx.pl <domain.(com|edu|net)> [o]
o => Output results to domain.zone.txt
";


# Get and check args and handle output
print $usage and exit unless defined(my $fqdn = shift);
print $usage and exit if $fqdn !~  /^[0-9a-z\-]+\.com|edu|net$/;

if (my $option = shift) {
	if ($option =~ /o/) {
		$where_to_print = 1;
		($domain, undef) = split(/\./, $fqdn);
		open $output, '>>', "$domain.zone.txt" or die ">>> Can't create $domain.zone.txt: $!";
		print $output ">>> dnsx.pl -\n\n";
	}
	else { print $usage and exit; }
}


# Print header
print ">>> dnsx.pl -\n\n";
print ">>> Printing output to $domain.zone.txt\n" if $where_to_print == 1;


# Parse whois query
my @lookup = `whois -h whois.internic.net $fqdn`;

foreach my $line (@lookup) {
	if ($line =~ /Name Server: (.+)$/) {
		if ($where_to_print == 1) {
			print $output ">>> Found name server: $1\n";
		}
		else { print ">>> Found name server: $1\n"; }
		transfer($1);
	}
}


# Perform transfer on each name server
sub transfer {
	my @zone_transfer = `dig axfr \@$_[0] $fqdn`;
	if ($where_to_print == 1) {
		print $output @zone_transfer;
	}
	else { print @zone_transfer; }
}